Dispersive Friedmann universes and synchronization

TL;DR

This paper explores dispersive modifications of Friedmann cosmology, revealing new long-term behaviors and demonstrating that dispersive Milne and flat universes can fully synchronize, potentially solving key cosmological puzzles.

Contribution

It introduces dispersive aspects into Friedmann equations and shows their impact on solution behaviors and cosmological problems, a novel approach in cosmology.

Findings

Dispersive Friedmann solutions exhibit unique long-term properties.

Dispersive Milne and flat universes synchronize completely in the future.

Potential resolution of horizon, homogeneity, and isotropy problems.

Abstract

We introduce consideration of dispersive aspects of standard perfect fluid Friedmann cosmology and study the new qualitative behaviours of cosmological solutions that emerge as the fluid parameter changes and zero eigenvalues appear in the linear part of the Friedmann equations. We find that due to their insufficient degeneracy, the Milne, flat, Einstein-static, and de Sitter solutions cannot properly bifurcate. However, the dispersive versions of Milne and flat universes contained in the versal unfolding of the standard Friedmann equations possess novel long-term properties not met in their standard counterparts. We apply these results to the horizon problem and show that unlike their hyperbolic versions, the dispersive Milne and flat solutions completely synchronize in the future, hence offering a solution to the homogeneity, isotropy, and causal connectedness puzzles.